Cartridge for pasty materials

ABSTRACT

A cartridge for pasty materials with two chambers for accommodating two components of a pasty material, wherein each chamber is provided with an outlet duct and a means for releasing the pasty material into an attachable mixing top part. A swivelable plate that is firmly mounted on the cartridge is closed in order to lock the plugs and the mixer and opened by using a swiveling action in order to insert and remove the plugs, replace the mixer and also for cleaning purposes.

The present invention relates to a cartridge for pasty materials.

Cartridges of such type are used not only as packaging containers for storing and transporting pastes, but also as a constituent of a system comprising dischargers, dispensing cartridges, dosing cartridges and mixers.

Dental elastic impression compounds in paste form are usually supplied in tubular foil bags or cartridges. The silicone oils, curing agents and catalysts contained in these pastes have high creep and diffusion properties. Therefore, the problem of sealing the cartridges exists particularly in case of dental elastic impression compounds made from vinyl polysiloxanes.

In double cartridges with a common opening for both components, as described in EP 0 232 733, EP 0 261 466, EP 0 294 672, one of the component outlet ducts got clogged frequently because constituents of the second component could creep over due to the direct contact of these ducts.

Also, the use of plugs on the sealings, as described in EP 0 431 347 or EP 0578 897, could not prevent the silicones from creeping in all cases.

The use of round outlet ducts that are separated for the individual components (e.g. EP 0 730 913, EP 0 733 022, EP 1 125 641 and WO 00/21653) could clearly suppress this tendency of creeping over. However, as a result of the bayonet locks used here for attaching the plug and the mixer statically or dynamically, the silicon oil could use the common sealing and/or the bayonet ring as a bridge and again creep over.

An additional disadvantage of these structures is that they were difficult to clean. Usually, in these systems, the user brings both components on the same discharge level before the first mixing by discharging one of the somewhat congested product chambers. In doing so, and also due to slight leakiness during the mixing process or in the mixer replacement between two uses, frequently some product gets smeared. Due to the outlet ducts located close to one another and the shapes of the bayonet holders, it is not possible to remove these smudges and stains. Thus, one of the ducts can get clogged by contaminants until the next application.

It is thus necessary to provide an improved and simplified cartridge.

This task is solved as specified herein by a cartridge for pasty materials comprising two cylindrical chambers arranged next to one another, each of which has a foot end with an opening and a piston that can be displaced in the direction of the cylinder axis in the respective chamber for the purpose of discharging the material contained in the chamber. The chambers each have a top end that lies opposite to the foot end and has at least one outlet opening, wherein each of the outlet openings has either a sealing plug or are connected to one another by a common mixing chamber arranged on top of them. The mixing chamber has a flange on its end turned toward the outlet openings. The cartridge in accordance with the invention is characterized in that a fixing plate is arranged at the top end of one of the chambers that can swivel between two stop positions. The fixing plate in the first stop position is arranged on a surface of both the sealing plugs and/or the surface of the flange of the mixing chamber that is turned away from the chambers in order to prevent a detachment of the sealing plug and/or the mixing chamber from the outlet openings, wherein the fixing plate in its second stop position is not arranged above the surface of the sealing plugs and/or the flange. In its first stop position, the fixing plate overlaps the sealing plug and/or the mixing chamber at least partly to the extent that is necessary for the purpose of avoiding these parts from getting detached from the chambers whereas in its second stop position the fixing plate releases the sealing plug and/or the mixing chamber for detachment purposes. Therefore, the fixing plate does not necessarily have to lie directly on the surface as long as the sealing plug and/or the mixing chamber automatically hold tight to the outlet openings. In case of pressure on the piston, however, the pressure on the mixing chamber placed on the outlet openings for dispensing the materials usually becomes so great that the mixing plate leans against the fixing plate.

The outlet openings are preferably designed as outlet ducts. The top ends of the chambers are designed as top plates that are arranged at the same level. It is advantageous if the surfaces of the sealing plugs and the surface of the flange of the mixing chamber turned away from the chambers are located at the same distance from the top plates. Furthermore, it is advantageous if reinforcing bars are arranged on the top plates outside the swiveling range of the fixing plate. In particular, the height of the reinforcing bars above the top plates is equal to the distance of the surface of the fixing plate turned away from the chambers from the top plates in order to achieve an even and stable support during its application in a discharger. The reinforcing bars extend axially around the periphery and/or perpendicular to the chambers. The outlet ducts of both chambers are sealed with separate plugs that, however, are locked in common by the swiveling plate.

The shape and size of the cartridges is determined by the application. The cartridges are particularly used for storing and discharging dental elastic impression compounds.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in more detail on the basis of the drawings of which:

FIG. 1 illustrates the cartridge with closed plug in the storage and transportation state,

FIG. 2 illustrates the cartridge with locked mixer (mixing chamber) for the application,

FIG. 3 illustrates the side view of the cartridge with fixing plate, and

FIGS. 4, 5 illustrate the top view of the cartridge in accordance with FIG. 3 with closed and opened fixing plate respectively.

The illustrated cartridge chambers have varying sizes and represent containers for the widespread application in the dental field in which the volume of a catalyst paste amounts to ⅕ of the volume of a base paste so that during use, there is a mixture, for example, of elastic impression compounds in predetermined ratio.

FIG. 1 illustrates the cartridge with two chambers 1,2 with outlet ducts 3,4 closed by plugs 5,6 in the storage and transportation state. The plugs are retained by means of the fixing plate 10 on the outlet ducts 3,4. The upper end of the chambers 1,2 is formed by top plates 16,17 that are arranged at the same level. The top plates 16,17 are stiffened by reinforcing bars 11,12,13,14. In the lower part of the chambers 1,2, displaceable pistons 7,8 are arranged that serve as means for dispensing the pasty material.

FIG. 2 illustrates the cartridge with locked mixing chamber 9, ready for use. The mixing chamber 9 attached on top releases the outlet ducts 3,4. It is retained on the cartridge by means of the fixing plate 10. FIG. 3 illustrates the side view of the cartridge with fixing plate 10 without plugs or the mixing chamber.

FIGS. 4, 5 illustrate the top view of the cartridge with closed and opened fixing plate 10, respectively, in the closed and opened state, respectively. Plugs or the mixing chamber are not illustrated in these figures for purpose of simplifying the description. Both the stop positions of the fixing plate 10 are formed by reinforcing bars. The upper edge of the reinforcing bars and the fixing plate 10 are at the same level. The fixing plate 10 has on its lower side turned toward the chambers 1,2 a projection 15 for attachment to the lateral edge of the plugs or the flange of the mixing chamber. Consequently, this ensures a reliable mounting of the fixing plate if the plug/mixing chamber is correctly attached on top. 

1. A cartridge for pasty materials comprising two cylindrical chambers arranged next to one another, each of said chambers having a foot end comprising an opening and a piston that can be displaced in a direction of a cylinder axis in the respective chamber for the purpose of discharging a material contained in the chamber, the chambers each having a top end that lies opposite to the foot end and has at least one outlet opening, wherein each of the outlet openings has either a sealing plug or is connected to one another by a common mixing chamber arranged on top of them, the mixing chamber having a flange on its end turned toward the outlet openings, wherein at the top end of one of the chambers, a fixing plate is arranged that can swivel between two stop positions, the fixing plate in a first stop position is arranged on a surface of both the sealing plugs and/or the surface of a collar of the mixing chamber that is turned away from the chambers in order to prevent a detachment of the sealing plugs and/or the mixing chamber from the outlet openings, and the fixing plate in a second stop position is not arranged above the surface of the sealing plugs and/or the flange.
 2. Cartridge pursuant to claim 1, wherein the outlet openings are designed as outlet ducts.
 3. Cartridge pursuant to claim 1, wherein the top ends of the chambers are designed as top plates that are arranged at the same level.
 4. Cartridge pursuant to claim 3, wherein surfaces of the sealing plugs and a surface of the flange of the mixing chamber turned away from the chambers are located at the same distance from the top plates.
 5. Cartridge pursuant to claim 3, wherein reinforcing bars are arranged on the top plates outside a swiveling range of the fixing plate.
 6. Cartridge pursuant to claim 4, wherein reinforcing bars are arranged on the top plates outside a swiveling range of the fixing plate.
 7. Cartridge pursuant to claim 5, wherein a height of the reinforcing bars above the top plates is equal to a distance of the surface of the fixing plate turned away from the chambers from the top plates.
 8. Cartridge pursuant to claim 6, wherein a height of the reinforcing bars above the top plates is equal to a distance of the surface of the fixing plate turned away from the chambers from the top plates. 